The present invention relates to an improvement in vehicle window cleaning arrangements of the kind which comprise a wiper arm which is pivotally journalled at one end and connected with a drive mechanism and which carries first and second wiper blades, of which the second blade is journalled for pivotal movement relative to the first blade and is connected to a linkage mechanism operative in varying the angle of the second wiper blade relative to the first wiper blade during pivotal movement of the arm.
One problem of long standing with regard to keeping vehicle windows, primarily vehicle windscreens or windshields, free from water and dirt, is found in the provision of a wiper which will leave the smallest possible area unswept. Parallel pivoting wipers leave an unswept area in the region of the windscreen posts, whereas other pivotable wipers leave unswept a V-shaped area in the centre of the windscreen or window.
In the case of windscreen wipers of this latter kind, it is known to provide one of the wiper blades with an additional blade which is pivotally mounted at one end of the outer extremity of the wiper arm, such as to function as an extension of the standard wiper blade and therewith reduce the unswept area. One such arrangement is described and illustrated in U.S. Pat. No. 2,787,018 and includes a linkage mechanism which when in its starting position holds the additional wiper blade as an extension of the standard blade. As the wiper arm of this arrangement approaches a vertical position, the additional blade is angled so as to place said blade at an angle to the standard blade and within the sweeping area thereof, from the time when the arm is located vertically to the time when it reaches its terminal position.
In recent years it has become more and more usual to equip estate cars and so-called tailgate or five-door saloons with rear window cleaning arrangements. These cleaning arrangements are normally of simple construction, i.e. they comprise a single, centrally located pivotable wiper arm, which pivots through an angle of about 180.degree. and which carries a single wiper blade. The width of the swept area is, in principle, restricted to twice the height, or vertical extension, of the window, which in the majority of cases means that a relatively wide area on both sides of the window remains unswept, i.e. is not cleaned.